Australia has entered a new phase in dealing with the deadly H5N1 bird flu, with authorities confirming on Wednesday that local transmission of the highly virulent strain has occurred among birds in South Australia. The announcement came after 11 new suspected detections were reported in greater crested terns, including four cases on Kangaroo Island, bringing the national total to 27 confirmed detections.
Local Transmission Confirmed
Julie Collins, the federal minister for agriculture, fisheries and forestry, stated on Wednesday afternoon: “We have had what is suggestive of local transmission for the first time.” She added: “We will expect to see increased evidence and deaths of wildlife … given there has been some local transmission. This small shift in the situation will be very disappointing to many, but is certainly not an unexpected development as the last continent to detect H5 bird flu.”
The Consultative Committee on Emergency Animal Diseases, comprising federal and state authorities, met on Wednesday and agreed that local transmission had occurred among greater crested terns resident in South Australia. Dr Beth Cookson, Australia’s chief veterinary officer, noted that genetic sequencing showed all confirmed cases were related to sub-Antarctic strains of the virus.
Kangaroo Island Sea Lions at Risk
One of the Kangaroo Island detections was at Seal Bay, home to Australia’s third-largest Australian sea lion population. Conservationists have expressed fears for this endangered species. Alexia Wellbelove, campaigns director at the Australian Marine Conservation Society (AMCS), said: “Australian sea lions are now on the frontline of the potential wildlife crisis.”
About 80% of the Australian sea lion population is found in South Australia. The species has seen numbers decline by 60% in four decades, with only about 12,000 remaining. Wellbelove warned: “In South America, this virus killed 30,000 sea lion pups in just six months following transmission from birds to marine mammals. On our own Heard Island, it killed more than 13,000 elephant seal pups in a single season … we now have to face the very real possibility of similar devastation here at home, in a species already teetering on the edge.”
SA minister for primary industries Clare Scriven said on-beach tours at Seal Bay were temporarily paused to keep people separate from the vulnerable animal population and reduce the risk of spreading infection.
Limited Options to Stop Spread
Dr Cookson acknowledged: “We do know from the overseas experience that once the virus becomes more widespread in wild bird populations it will not be possible to avoid losses in susceptible wildlife in the natural environment.” Authorities had anticipated H5N1’s arrival through migratory birds for years. They will continue surveillance to confirm where the virus is circulating and reduce impacts where possible.
Collins said the federal government had invested more than $113 million preparing for the virus’s arrival, and had recently released a further $24 million. Cookson noted the government was taking actions for high-priority conservation species, including site- and species-specific planning, protecting captive breeding populations, and implementing farm biosecurity measures to limit contact between wild birds and poultry.
Groups including the AMCS and the Invasive Species Council have called for a $200 million national wildlife resilience fund focused on emergency protection and recovery for at-risk species.
Potential Impact on Wildlife and Poultry
Worldwide, H5N1 has caused unprecedented outbreaks, killing millions of wild birds and tens of thousands of mammals. In Australia, more than 150 native bird species have been assessed as at very high risk of extinction or major decline if infected, including the red goshawk, fairy tern, plains-wanderer, shy albatross, black swan and western hooded plover. More than 10 mammal species are at very high risk, including the Australian sea lion, subantarctic fur seal and Australian fur seal.
The poultry industry also faces significant threats. Globally, an estimated 140 million farmed birds have died or been culled since January last year. In the United States, the virus was linked to a 220% spike in egg prices in the first quarter of 2025. Western Australia’s Chamber of Commerce and Industry warned that if the virus reached commercial flocks, it could push egg prices above $10 a carton. Mass culls may be necessary, and the RSPCA has called for fast-tracked research into more humane killing methods.
Human-to-human transmission remains uncommon, but since 2003 there have been 1,000 reported cases of H5N1 in humans globally, with a 48% fatality rate. Collins reiterated: “The risk to human health remains low.”
